﻿<p>The open profile <em>IfcArbitraryOpenProfileDef</em> defines an arbitrary two-dimensional open profile for the use within the swept surface geometry. It is given by an open boundary from which the surface can be constructed. </p>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC2x.
</blockquote>

<p class="spec-head">Informal Propositions:</p>
<ol>
  <li>The <em>Curve</em> has to be an open curve.</li>
</ol>

<p>Figure 2 illustrates the arbitrary open profile definition. The <em>Curve</em> is defined in the underlying coordinate system. The underlying coordinate system is defined by the swept surface that uses the profile definition. It is the xy plane of: </p>
      <ul>
        <li><em>IfcSweptSurface.Position</em></li>
      </ul>
<p>The <em>Curve</em> attribute defines a two dimensional open bounded curve.</p>

<table>
<tr><td><img src="../../../figures/ifcarbitraryprofiledef-layout3.gif" alt="arbitrary profile without boundaries" border="0" height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 2 &mdash; Arbitrary open profile</p></td></tr>
</table>